Getting readable results from Net::SNMP get

fingers has asked for the wisdom of the Perl Monks concerning the following question:

I am trying write a script that will poll cisco gear for information regarding it's CDP neighbors.

I had pretty much completed the project using telnet to get the information I wanted when I realized it would be quicker and less intrusive to gather this info with SNMP. I tracked down the appropriate oid and am using the Net::SNMP get_table method. It seems to be working, but I am getting output that looks like this:

HASH(0x82753ec)

What do I need to do to extract some meaningful information from this?

I have read the docs on the Net::SNMP module and am feeling very obtuse right now. I would love to see some actual examples of the get_table method if anyone has any existing code that uses it.

This is the pretty bare bones code I am using to test this method.

#!/usr/bin/perl -w
use Net::SNMP;
# requires a hostname and a community string as its arguments
($session,$error) = Net::SNMP->session(Hostname => $ARG[0], Community 
+=> $ARGV[1]);
die "session error: $error" unless ($session);
#1.3.6.1.4.1.9.9.23.1.2.1.1 is the OID that the CDP info starts at
$result = $session->get_table("1.3.6.1.4.1.9.9.23.1.2.1.1");
die "request error: ".$session->error unless (defined $result);
print "$result \n";
$session->close;
[download]

Thanks in advance on any light you can shine on this. I do believe that my eyes will start bleeding if I stare at any more docs.

Comment on Getting readable results from Net::SNMP get_table method Download Code

Replies are listed 'Best First'.
(Ovid) Re: Getting readable results from Net::SNMP get_table method by Ovid (Cardinal) on May 16, 2001 at 03:32 UTC
Data::Dumper is a quick and easy method of seeing what's really in variables. In this case, the scalar `$result` appears to be a reference to an anonymous hash. Try this: `use Data::Dumper; print Dumper( $result );` [download] That will let you see what you're getting back. Cheers, Ovid Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.	[reply] [d/l]
Re: Getting readable results from Net::SNMP get_table method by srawls (Friar) on May 16, 2001 at 03:36 UTC
Whenever you see code like this: `HASH(0x82753ec)` then you are referencing the entire hash, this is obviosly not what you want, so try this: `print "$result{$_}\n" for keys $result;` [download] I am not familiar with the module you are using, but I think this code should work; if you have any more questions - just ask. UPDATE: Thanks Ovid, I missed that one. The 15 year old, freshman programmer, Stephen Rawls	[reply] [d/l] [select]
Re: Re: Getting readable results from Net::SNMP get_table method by Ovid (Cardinal) on May 16, 2001 at 03:52 UTC
Close, but here's what you actually want. `print "$result->{$_}\n" for keys %$result;` [download] Cheers, Ovid Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.	[reply] [d/l]
Re: Re: Re: Getting readable results from Net::SNMP get_table method by fingers (Acolyte) on May 16, 2001 at 04:29 UTC
When I use `print "$result->{$_}\n" for keys %$result;` [download] I get output that looks like `HASH(0x82a08e0)->(1.3.6.1.4.9.9.23.1.2.1.1.8.4.2)` [download] when I use the Data::Dumper module you suggest I get results that look like. `'1.3.6.1.4.9.9.23.1.2.1.1.8.4.2' => 'WS-C6509'` [download] I assume that the oid is the key and the WS-C6509 is the object in the hash. How would I pull that all into hash that I would be able to manipulate?	[reply] [d/l] [select]
Re: Re: Re: Re: Getting readable results from Net::SNMP get_table method by mr.nick (Chaplain) on May 16, 2001 at 05:22 UTC
Accessing a value without knowing the key by fingers (Acolyte) on May 16, 2001 at 06:59 UTC
Now that I can print out the entire hash and I know that I'm getting the data that I eventually want to use. I am stuck at trying to figure out how to access values in my hash without knowing exactly what the keys are.	[reply]
Re: Accessing a value without knowing the key by dws (Chancellor) on May 16, 2001 at 08:32 UTC
I am stuck at trying to figure out how to access values in my hash without knowing exactly what the keys are. `@values = values %hash;`	[reply] [d/l]
Re: Getting readable results from Net::SNMP get_table method by Anonymous Monk on Feb 16, 2017 at 13:46 UTC
after giving oid can i use grep in get_table	[reply]
Re: Getting readable results from Net::SNMP get_table method by mr.nick (Chaplain) on May 16, 2001 at 05:02 UTC
(deleted) Bzzzt! Sorry, I messed up. I'm not sure what I was thinking.	[reply]


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Getting readable results from Net::SNMP get_table method